Button sewing machine



Oct. 29, 1957 Filed une 2s, 1954 c J. M. BENINK BUTTON SEWING MACHINE 4 Sheets-Sheet 1 Oct. 29, 1957 c. J. M. BENINK 2,811,122

BUTTON SEWING MACHINE Filed June 23, 1954 4 SheetsSheet 2 OCL 29 l957 c. J. M. BENINK r 2,811,122

BUTTON SEWING MACHNE Filed June 23, 1954 4 Sheets-Sheet 3 Oct. 29, 1957 C, J, M BENlNK 2,811,12?I

BUTTON SEWING MACHINE Filed June 23, 1954 4 Sheets-Sheet 4 United States Patent@ BUTTON SEWING MACHINE Christian J. M. Benink, Kaiserslautern, Germany, assignor to G. M. Pfaff A.G., Kaiserslautern, Pfalz, Germany, a corporation of Germany Application .lune 23, 1954, Serial No. 438,717 Claims priority, application Germany September 23, 1953 7 Claims. (Cl. 112-110) The invention relates to button sewing machines of the type having a predetermined operating cycle and means for automatically raising and lowering the button clamp.

The invention has among its objectives to provide such a machine in which the raising of the button clamp at the end of the cycle is energized by suddenly releasing spring energy, and which includes means for storing spring energy during the cycle, and means restraining premature lifting of the button clamp.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawings, in which:

Fig. 1 is a side elevational view of a button sewing machine in accordance with the invention, showing the parts positioned prior to the start of the operating cycle;

Fig. 2 is a rear elevational view of the machine shown in Fig. 1;

Fig. 3 is a plan view of the machine shown in the preceding views;

Fig. 4 is a large scale fragmentary elevational view of a portion illustrated in Fig. 1, but with the parts in a position during the operating cycle;

Fig. 5 is a fragmentary sectional View taken on line 5 5 of Fig. 4; and

Fig. 6 is a fragmentary sectional view taken on line 6-6 of Fig. 4.

In carrying the invention into eect in one of the embodiments which has been selected for illustration in `the accompanying drawings and for description in this specification, and referring now particularly to Figs. 1-3, there is provided a button sewing machine that has a frame structure 1 that surmounts a work tablek 4. The frame structure 1 includes an arm 2 and a front head 3. The drive for the machine is taken ofI a belt (not shown), that is shiftable between a pulley 5 that is fixed to the machine shaft (not shown) and an idler pulley 6. A shifting fork 9 is provided at the rear end of the machine, to shift the belt between the lixed pulley 5 and the idler pulley 6. Theshaft (not shown) on which there is mounted the fixed pulley 5 is in driving connection with a main or control shaft 7 on which there are mounted for rotation therewith a control disk 8 and a flange 35 that 'carries a cam disk 36 (Fig. 3).

A shifting lever is provided at the rear end of the machine, and the shifting fork 9 is connected to the lever 10 so that upon rearward shifting of the shifting lever 10, in direction A, the belt will be shifted from the idler pulley 6 to the fixed pulley 5; conversely, upon forward shifting of the lever 10, in the directon E, the belt will be shifted from the fixed pulley 5 to the idler pulley 6. When the machine is at rest, the belt energizes the idler pulley 6.

An elongated flat shifting rod 12 is connected to the shifting lever 19 by means of a screw 11, and is pivotably supported by a lug 13 that is pivoted on the arm 2; the

2,811,122 l atented Oct. 2v9, 1957 ment 14 furthermore includes an arm 18 that carries a set screw 19 on'which there is mounted a lock nut 19a.

Adjacent the arm 2 of the machine, and above the forward end of the rod 12, there is disposed a tripping lever 20. The tripping lever 20 is pivoted at its forward end at 20a to a lifting lever 21. The tripping lever 20 is urged in a forward direction, substantially in direction E, by a tension spring 22 that is anchored in the head 3.

Near its rear end, the tripping lever 20 carries an olfset piece 23 that has a front surface 23a (Figs. 3 and 4) for engagement with the surface 16a, and has a rear terminal that has a rearwardly facing cam surface 24. The piece 23 is connected to the rear end of the tripping lever 20 by means of two screws 25 (Figs. 4 and 6), and has a bottom surface 23b for abutment against the top surface 17. The rear portion of the tripping lever 20 is guided in a channel 46 (Figs. 4 and 6) as explained below.

A tiltable lever 26 is pivoted at 31 to the arm 2 of the machine. The Vlever 26 includesra rear arm 26a and a front arm 26h. The lifting lever 21 is pivoted at 26e to the front arm 2Gb of the lever 26. The rear arm 26a of the lever 26 is offset and carries a cam follower roller 34 in a slot 33. Thercam follower 34 cooperates with the cam disk 36 to impart to the lever 26 a reciprocal tilting movement about the pivot 31, for tilting the front arm 26b downwardly (Fig. 4) and upwardly (Fig. 1), respectively. A retraction tension spring 32 is connected to the head 3 and to the front arm 26b and urges the front arm 26b into the upper position shown in Fig. 1.

Above the work table 4 there is provided a button clamp 29 that is reciprocably movable arcuately, namely downwardly in direction D and opposite thereto upwardly. The clamp 29 is provided with a pin 28 for releasable engagement bythe lower end of the lifting lever 21.

As the forward arm 26b is lowered and raised the lifting lever 21 will correspondingly move down (in direction D) and up. The reciprocating forward and rearward movement of the tripping lever 20 on the other hand, will impart to the lifting lever 21 an arcuate movement about the pivot 26e, which forces the lower end vof the lifting lever 21 to` describe an arcuate path that is at an angle to the path in direction D and opposite thereto of the button clamp 29. This movement of the lifting lever 21 serves for the engagement with, and disengagement from, the pin 28 by the lower end of the lifting lever 21.

A compression spring 30 is provided that urges the clamp 29 downwardly in direction D, but this spring is weaker than the spring 32.

The cam disk 36 is interchangeably connectedto the ange 35 that is secured tothe control shaft 7. The cam disk 36 is mounted for rotation in direction B (Fig. l), and is provided with liftingicams 38, and a guiding cam 37 adjacent each lifting cam 38. y

The number of cams 37 and 38 on the cam disk 36 depends on the number ofrstitching groups;`in the exemplilication of Fig. l, there are shown two cams 37 and two cams 38 for an exemplified two stitching groups.

The 'cam disk 36 furthermore carries bolts, such as the two bolts 39 shown, for cooperation with the c am surface 24 ofthe piece 23'that-is mounted on the tripping lever 20. In the position shown ,in Fig. 1, the -cam surface 2.4k projects into the 4circular path of therbolts 39 -to'br engaged thereby upon impact with the bolt 39 for raising the rear end of the tripping lever 20 from the position shown in Fig. l into the position shown in Fig. 4.

As best shown in Figs. 4-6, a bracket 40 is secured by means of screws 41 and 42 to the arm 2.

The bracket 40 has a lower part 43 that is bent outwardly and has a vertical slot 40a that serves as a guide for the rod 12. An angle piece 44 is secured to the lraised by the lifting lever 21. To `restrain any premature lifting of the clamp 29, means are provided for releasably latching the tiltable lever 26 in the position of Fig. 4. This means includes a'latch 48 that is pivoted at 49 to the bracket 40. A spring 50 urges the `latch 48 in direction G. The latch 4Shas atop surface '51 that Vengages the lower surface of a latching piece S2 which is mounted by screws 53 on the lever 26. When the lever 26 has been moved from the position shown in Fig. l to that illustrated in Fig. 4, the latch 48 will engage the piece 52 for maintaining the rear arm 26a in the raised position and consequently holding `the front arm 2Gb in the lowered position. Y

The latch 48 has a lower extension 54 (Fig. 4) that is disposed opposite the set screw 19 for engagement thereby. By a forward 'movement of the rod 12 lin the direction E, the set screw 19 will press against the extension 54 of the latch 48,'turning it indirection F, so that the engagement between the latch 48 and the latching piece 52 will be released, in timed relationship with I the position of the cam disk 36, so that the lever 2.6.may return to the initial position shown in Fig. 1.

The operation of the above described machine is as follows.

To start the machine, the operatorwillmove the lever in direction A; By this, movement, the Yfork 9 will transfer the beltfrom the idler pulley6 tok the fixed pulley S, starting the rotationof the; control shaft 7 and therewith of the cam disk 3.6, At the sameY time, this operation will cause a rearward movement in direction :A of the rod 12. As best shown in Fig. 1in the initial position the rear face 16a of the element 14 of they rod 12 abuts against the front face 23a of` the, piece 23: that isrconnected to the tripping lever 20.1, Accordingly,idur .ing the aforementioned rearward movement of the rod 12, the element 14 will push rearwardly, substantially -in direction A, the tripping lever v against, the power of the spring 22. By this rearward movement of the tripping lever 20, the spring 22 is being set, and tension :energy is stored in it. The rearward `movement of the tripping lever. 20 causes a rearward arcuate movement of the lifting lever 21, in direction C, resulting in release `of the pin 28.Y Thereupon, the spring will press the .clamp 29 downwardly in direction D. f

During the cycle of operation, asY theY cam Ydisk 36 turns in direction B, the cam 38 willv liftzthe roller 34 and will thereby turn upwardly the rear arn1'26a` of the 'tilting lever 26 about the pivot 31. By this movement, the front arm 26h will correspondingly ybe lowered against the power of the retraction spring 32. Tension Venergy is thereby stored inthe spring 32,. The cam 38 and the dimensions ofthe various parts areso arrangedthat the downward movement of they forward ,2 .6b'is continued until the lower end Qt the Ylifting lever 2.1 iS posi- .nosed-1.1.1 arcuate alignment., about rthe pivot, 2.6., with fthe.- pin 2,785 In this position, the lifting .lever 21, may engage. thepin 28 upon arcuate forward'movement in a direction opposite to the direction C. At the instant under observation, however, the lifting lever 21 is angularly spaced from the pin 28 owing to the rearward position of the tripping lever 20 as described in the foregoing.

During the ensuing stitching operation, the roller 34 engages the outer circumference of the cam disk 36, with the lever 26 being in tilted position shown in Fig. 4. During the rearward movement of the rod 12 made at the beginning of the operation by the operator, the set screw 19 has been moved away from the extension 54 of the latch 48, and the spring S0 has pressed the latch 48 in direction G into a position in which the surface 51 supports the latching piece 52. This provides for locking of the lever 26; it restrains lifting of the forward arm 26h prematurely while the stitching operation is still in progress. This locking has the advantage that premature return movement of the tilting lever 26 will be prevented even if the outer circumference of thercam disk 36 should not be perfectly true, or the intersection between the cam 37 and the outer circumference of the cam disk 36 be no longer accurate, for instance owing to the prolonged use.

Towards; the end of thev stitching operation, a bolt 39 will strike against the cam surface 24 of the piece 23 and will lift the piece 23 so that the face 23a will be disengaged from the face 16a, and the lower surface 2312 will come to rest on the top surface 17 of the element 14. In this position, the spring 22 will move the tripping lever A20 forwardly, substantially in direction E, thereby moving the Vlifting lever 21 about the pivot 26e in a direction opposite to the direction C so that the lower end of theV lifting lever 21 will engagethe pin 28. At the moment ofk thisl engagement, the clamp 29 is still in the lower position, and 'also theforward arm 26h is 1 iin the lower position (Fig. 4).

For completing the cycle, all that is` necessary will be to lift the forward arm 26b causing a lifting of the clamp 29Vowing to the engagement of the lifting lever 21 with the pin 28.

At the end of the. stitching operation, the machine will be switched oif,with a forward movement of the lever 10, in direction E. That forward movement brings about a corresponding movement inthe direction E of the rod 12. During this movement, the set screw 19 will engage the extension 54 and will turn the latch v48 about the pivot 49 in the direction F to release the latching piece 52. At this instant, the cam 37 will be in position shown in Fig. l. The position of the cam 37, as well asthe release by the latch 48 now permit the retraction spring 32 to lift the forward arm 26b for returning the lever 26 to the original position (Fig. 1). Duringthis movement caused by the retraction spring 32, the liftinglever 21 will be lifted and will take along the pin 28' as well as the clampr29, lifting the clamp 29 against the power ofthe spring 30.

It will be`.apparent to those skilled in the art that the novel principles of the invention disclosed herein inconnection with specific exempliication'thereof will suggest various` other modificationsy and applications of the same. lt is accordingly desired that in construing the breadth of the appendedl claims they shall not be limited to the specific exemplication of the invention'described herein.

Having thus described the invention, what I claim as new and desire-to be secured `by Letters Patent is as follows:v

1. In a button sewing machine having a work support and a frame `abovesaid support, stitch forming'ele'ments and a needle, driving means for said elementsV and said needle, and a switch member to start the operating cycle of the machine,.in combination, a mechanism operable independently of the needle operation comprising a button clamp hinged to. said work support and being movable upwardly from a normal position opposite said lneedle adjacent said work support, first spring means urging said clamp towards said normaly position, a tilting lever pivoted to said frame and tiltable upwardly and downwardly, cam means connected to said frame and being in driven connection from said driving means and operable releasably to lower said tilting lever, a lifting lever pivoted to said tilting lever and operable to be raised and lowered thereby and being tiltable at an angle to the direction of its lifting and lowering movement between a first position and a second position at an angle thereto and including means for releasably engaging said button clamp in said iii-st position and, respectively, to release said clamp when moved from said rst to said second position, a tripping lever connected to said lifting lever and operable for tilting it, engaging means connected to said switch member and operable to releasably engage said tripping lever for moving said tripping lever in one direction to move said lifting lever from said first to said second position, second spring means operable to retract said tripping lever in an opposite direction upon release from said engaging means to return said lifting lever to said rst position, third spring means connected to said tilting lever urging the same upwardly and being stronger than said first spring means, and release means operated from said driving means for disengaging said tripping lever from said engaging means, whereby at the start of the operating cycle. said switch member will be engaged to said tripping lever and move it in said one direction to move said lifting lever towards the second position thereby releasing said button clamp, and towards the end of the operating cycle said cam means will lower said tilting lever thereby tensioning said third spring means and said release means will disengage said tripping lever from said engaging means enabling said second spring means to retract said tripping lever moving said lifting lever to said rst position wherein it will engage saidclamp, and said third spring means will raise said tilting lever and thereby said lifting lever and said clamp against the force of Said iirst spring means.

2. In a button sewing machine, as claimed in claim l, together with, said switch member being operable to return upon cessation of the operating cycle, means connected to said frame and operable for immobilizng said tilting lever in the lower position during the major part of the sewing machine operating cycle, and means connected to said engaging means and operable upon the return thereof to release said immobilizng means for releasing said tilting member to be lifted by said third spring means.

3. In a button sewing machine, as claimed in claim 2, said immobilizng means comprising a spring tensioned two-armed safety latch pivoted to said frame and operable to latch with its upper arm said tilting lever, the lower arm being disposed in the path of said engaging means, said engaging means being operable to engage said lower arm during its retraction -to turn said latch to release said tilting lever.

4. In a button sewing machine, as claimed in claim 2, said cam means including a control disk driven from said driving means and having cam surfaces, and a contact roller adjustably arranged at one end of said tilting lever and forming a cam follower for said cam surfaces.'

5. In a button sewing machine working in a controlled operating cycle and having a needle and driving means and control means for controlling the cycle including a main shaft and a cam disc driven by said driving means, in combination, a button clamp movable between a lowered and a raised position and biased towards the lower position, and an operating mechanism operable independently of the needle, to lift said clamp to the raised position comprising a spring tensionable for storing energy therein to energize therefrom the lifting of the clamp, a cam follower engaging said cam disc and being interconnected to said spring and operable for releasably `tensioning said spring, movable means connected to said cam follower and being operable to interconnect the clamp temporarily with the cam follower and thereby with the spring for lifting of the clamp by the spring against said bias upon spring tension release and respectively, to disconnect the clamp from said cam follower and thereby from said spring for subsequent return of the clamp under the bias, and means operable to actuate said movable means in timed relation of said cycle to complete the disconnection near the commencement of the cycle and, respectively, to complete the interconnection near the end of the cycle.

6. In a button sewing machine as claimed in claim 5, said operating mechanism including a tripping lever movable between two positions and biased to be normally in one position, and cycle starting means being operable to move said tripping lever against said bias.

7. In a button sewing machine as claimed in claim 6, together with, means connected to said cam disk and operable for releasing said tripping lever from the engagement by said starting means` References Cited in the file of this patent UNITED STATES PATENTS 931,700 McLaughlin et al Aug. 17, 1909 2,116,889 Gunther May 10, 1938 2,300,585 McCann Nov. 3, 1942 2,361,032 Ibbot Oct. 24, 1944 2,367,187 Collins Ian. 16, 1945 2,540,987 McCann Feb. 6, 1951 

